Genome sequencing of Pseudodesulfovibrio paucinitrogenus, a nitrogen-fixing sulfate-reducing bacterium isolated from mangrove sediment

Pseudodesulfovibrio paucinitrogenus, is a novel sulfate-reducing bacterium isolated from mangrove sediment in Xiamen, China, capable of biological nitrogen fixation under N-free conditions. This strain utilizes lactate as an electron donor and sulfate as an electron acceptor, and its genome harbors both nif (molybdenum-dependent) and anf (iron-only) nitrogenase gene operons, enabling diazotrophic growth. Genomic surveys reveal that the majority of described Pseudodesulfovibrio type strains possess nif operons, supporting the proposal of Pseudodesulfovibrio as a bona fide nitrogen-fixing genus. This genome provides insights into the ecological role of SRB in nitrogen cycling in coastal ecosystems.